Image capturing devices as cameras are often based on single or multiple sensor chips. The sensors of the cameras based on a single sensor chip may have multiple photosensitive pixel cells. Said pixel cells may each be provided with color filters having different or similar colors on top of each of the photosensitive pixel cells. The filters enable each pixel cell of the image sensor to capture multiple light spectra or color components for each pixel as a basic image component.
One of the frequently used color filter pattern is a so called “Bayer” pattern, wherein a color filter array is provided for arranging red, green and blue (RGB) color filters on a square grid of photosensitive pixel cells. The Bayer pattern is provided with a set of red, green and blue color filters on top of a four pixel cell block each to create one red, one blue and two green sensitive pixels. The captured values from these pixel cells are called raw data.
Since each pixel is filtered to record one of three colors, the data from each pixel cannot fully specify each of the red, green, and blue values on its own. However for displaying a color image at least 3 color values for each pixel cell position are necessary. To obtain a full color image, an algorithm can be used to interpolate a set of red, green, and blue values for each pixel. These algorithms make use of the surrounding pixels of the corresponding colors to estimate the values for a particular pixel.
For this reason the raw data can be processed to three color components values (typically RGB values) for each pixel cell position. This process is known e.g. as a “demosaicing” process. This can be done by linear interpolation of same colored pixel cells or a more sophisticated method. In this process the raw data will disadvantageously be expanded to an RGB image and the amount of data is increased by a factor of 3.
It is a purpose of the present disclosure to overcome the drawbacks associated with raw images and to allow for an easier handling thereof in order to, for instance, allow for an easier encoding of raw data images.